Hello, I am new in Shopify and dont know much on how it works. I want to make an e-shop that has different stores owned by different owners. I want to calculate a commission for a store each time a client buys a product and sets the delivery at this specific store. I want to know how much money I owe at a specific store claculated from the products that were delievered at it. Hope it make sense...

I believe I understand what your intentions are here, but feel free to let me know if this doesn't accurately describe what you are looking for!

What springs to mind is the functionality offered by the Bold Marketplace App, which allows you to create a marketplace on your store where multiple sellers can list their products and for each sale you receive a commission.